The growing tips of my crabapple were covered in greenfly. I sprayed the tips with diluted washing up liquid. It successfully killed the greenfly but has browned and deadened the growing tips. I've cut the tips to remove the dead ends. Does this mean that the tree won't now grow any higher?

8 Jun, 2011

Answers

No, it doesn't mean that, but it is a very valuable lesson you've learned there. People commonly think that washing up liquid diluted in water is a harmless and environmentally friendly thing to do - it absolutely is not UNLESS the liquid concerned is an eco friendly one, and will in fact cause as many problems in the environment as pesticides. It also only works on contact, so those you manage to get rid of today with the solution will be replaced by another lot the next day, or even in the next hour. In future, choose a spray pesticide that treats for the problem, so if its only aphids, just buy one that treats for aphids and not a whole bunch of other pests - as you're not going to eat the fruit, you can use a systemic one that is effective on the plant for up to 2 weeks. Lecture concluded, lol;-))

Most washing up liquids aren't dangerous for plants...if they are diluted properly!! Many people carelessly squeeze an unknown amount of the liquid into a liter spray bottle, fill it with water, and spray away--sometimes with sketchy shaking! The right way is to mix about 3 ml of the liquid (preferably eco-friendly, see below) per liter of warm water, and mix thoroughly with a swizzle stick, to prevent foaming.
The danger with non-organic ones is that soil bacteria have a hard time digesting them, so they and their potentially toxic by-products tend to build up in the environment. The eco-friendly ones break down completely into plant nutrients fairly quickly, with minimal danger of contaminating the ground water or surrounding surface waters.